Very important message

Hello. I bought a book from "leslibrairies.ca" and i am trying to open it in Adobe Digital Editions because the file is URL.acsm format. I activated the Adobe id (the same email i used to buy the book in "authorized  users" section, and i put the same password). When i open the file in Adobe digital editions, it tells me E_LIC_ALREADY_FULLFILLED_BY_ANOTHER_USER. How can i resolve the problem? I have an exam next week and it's very important. Thank you very much!